The primary objective of the study is to evaluate the safety and tolerability of treatment with PROVIGIL in children and adolescents with excessive sleepiness (ES) associated with narcolepsy or OSAHS, when administered for up to 12 months.

The secondary objective of the study is to evaluate long-term effectiveness by using: the Clinical Global Impression of Change (CGI C) ratings for severity of ES and the total score from the Pediatric Daytime Sleepiness Scale (PDSS)

To evaluate the efficacy of pitolisant in reducing residual Excessive Daytime Sleepiness (EDS)

To evaluate the efficacy of pitolisant in reducing the number of cataplectic episodes (for patients with cataplexy)

To determine safety in children and adolescents - Safety assessment will be done on monitoring of adverse events, physical examination, vital signs, ECG (QTc) and Blood Laboratory tests modifications and the mood appraisal

Evaluate the effectiveness of ADX-N05 compared to baseline in adults with narcolepsy as determined by the Maintenance of Wakefulness Test following 2 weeks of treatment with ADX-N05 vs. 2 weeks of treatment with placebo

Evaluate the effectiveness of ADX-N05 compared to baseline in adults with narcolepsy as determined by the Epworth Sleepiness Scale following 2 weeks of treatment with ADX-N05 vs. 2 weeks of treatment with placebo

Evaluate the effectiveness of ADX-N05 compared to baseline in adults with narcolepsy as determined by the Clinical Global Impression-Change score following 2 weeks of treatment with ADX-N05 vs. 2 weeks of treatment with placebo

Evaluation of risk for development adverse events, withdrawal syndrome and potential for dependence, abuse, overdose and misuse of Xyrem®. Obtaining information about adherence to Xyrem® prescribing information regarding indication and dosage.